Endoluminal device with retractor system

ABSTRACT

Improved methods and devices for performing an endoscopic surgery are provided. Systems are taught for operatively treating gastrointestinal disorders endoscopically in a stable, yet dynamic operative environment, and in a minimally-invasive manner. Such systems include, for example, an endoscopic surgical suite. The surgical suite can have a reversibly-expandable retractor that expands to provide a stable, operative environment within a subject. The expansion can be asymmetric around a stabilizer subsystem to maximize space for a tool and an endoscope to each be maneuvered independently to visualize a target tissue and treat the target tissue from outside the patient in a minimally invasive manner.

This application is a continuation of application Ser. No. 13/862,340,filed Apr. 12, 2013, which is a continuation of application Ser. No.13/531,477, filed Jun. 22, 2012, now U.S. Pat. No. 8,932,211 and acontinuation-in-part of application Ser. No. 12/970,604, filed Dec. 16,2010, now U.S. Pat. No. 8,506,479, which claims priority fromprovisional application Ser. No. 61/287,077, filed Dec. 16, 2009. Theentire contents of each of these applications are incorporated herein byreference.

BACKGROUND

Field of the Invention

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically in a stable, yet dynamic operative environment, and in aminimally-invasive manner.

Description of the Related Art

Endoscopic procedures involving the gastrointestinal system offeradvantages over conventional surgery in that they are less invasive andprovide direct visualization. These procedures continue to evolve toaddress problems and provide new methods of treatment identified bythose skilled in the art.

One current problem includes a lack of technology for an optimalminimally-invasive expansion of a stable, working space adjacent to thetarget tissues that could otherwise collapse around the target lesion ordefect during an operative treatment. Having the ability to effectivelyexpand and optimally reconfigure the working space could markedlyfacilitate an intra-luminal operation. A better expanded, stable andoptimally configured working space allows the instruments and endoscopeto be independently manipulated and properly visualized around thetarget tissue. One of skill would appreciate having the ability to seeand approach both the target tissue and the surrounding anatomy forreference, orientation, and surgical maneuvering.

Another current problem includes a lack of an endoscopic technology fornot only expanding, but also affixing and stretching, both the targettissue and surrounding tissue. In a bowel, for example, such a stableoperative space could include a space that is non-collapsible, withlimited peristalsis or aperistaltic, and/or affixed at a particularpoint in the abdominal cavity. The fixed point can be considered fixedin relation to, for example, a fixed body point in the patient, such asthe patient's hip. Significant bowel movement is considered to be highlyundesirable during an operation on the bowel, for example, since it maycreate a challenging, unstable operative environment. Such bowelmovement is normal, of course, even in a sedated patient and can becaused, for example, by bowel collapse from an air leak, peristalsis,breathing, and movement of the scope and instruments. Having atechnology to overcome this problem would help provide a stableoperative space, which is clinically desired by one of skill in theoperative environment.

Another current problem includes a lack of an endoscopic technology forretracting the tissue dynamically, for example, through an adjustabletissue retraction structure allowing for a controlled degree ofexpansion or collapse of the structure, to further configure the workingspace as desired between the instruments and target tissue. Such controlcan effectively provide for a method of adjusting the retractor, as wellas tissue placement, in-and-around the working space. By increasing andreleasing the tension on the retractor, the amount of tissue to beplaced in the working space, for example, can be better-gauged andcontrolled during a procedure. Moreover, the tissue retraction and,particularly, traction-contra-traction can be facilitated to help createa desired dissecting plane or position the tissue more optimally duringan operation. Having a technology to overcome this problem would helpcreate an operative environment that is more desirable for tissuedissection, retraction, cutting and a removal of tissue.

Another current problem includes a lack of an endoscopic technology fororganizing the endoscope, instruments, and working space in a mannerthat can maximize the working space for the treatment. The larger spacecan improve the ability to manipulate the instruments and endoscope in aminimally-invasive manner from outside the body. Namely, one of skillwould like to have a working space that has a point of entry for theinstruments that is as far as practical from the target tissue toprovide additional flexibility in approaching and visualizing the targettissue, perhaps providing more operating room for selecting a trajectoryof the instruments toward the target tissue that is, for example, atleast substantially perpendicular to the plane of dissection of thetarget tissue. Having a technology to overcome this problem wouldprovide the person of skill with a system and procedure that is moredesirable for a removal of tissue.

In view of at least the above, one of skill in the art of endoscopic,gastrointestinal surgical treatments would appreciate the technologytaught herein which provides (i) a minimally-invasive expansion oftarget tissues; (ii) an affixing, particularly an affixing that includesa reconfiguring without stretching or reconfiguring with stretching, ofboth the target tissue and surrounding tissue to help provide a stable,operative space; (iii) a retracting of the tissue dynamically, allowingfor a partial or complete expansion or collapse, to further configurethe working space between the instruments and the target tissue; and(iv) an organization of the endoscope instruments, such as the retractorand tools to maximize the working space and maneuverability, allowingfor a maximum flexibility in approaching and visualizing the targettissue. It should be appreciated that having such improvements wouldreduce the technical complexity, and increase the efficacy and safetyof, otherwise complex endoscopic operations. Moreover, doing so at a lowcost, while using an affordable system that is introduced in the subjectatraumatically and in a manner that does not substantially disrupt theconventional colonoscopy workflow, would be seen by those of skill as avery substantial advancement in the field endoscopic surgicalprocedures.

SUMMARY

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically in a stable, yet dynamic operative environment, and in aminimally-invasive manner. The systems, for example, include anendoscopic surgical suite. The surgical suite can have areversibly-expandable retractor that expands to provide a stable,operative environment within a subject. The expansion can be asymmetricaround a stabilizer subsystem to maximize space for a tool and anendoscope to each be maneuvered independently to visualize a targettissue and treat the target tissue from outside the patient in aminimally invasive manner. Embodiments taught herein provide, amongother improvements, an increase in distance between tool ports and thetarget tissue to improve maneuverability and triangulation of the toolswith respect to the target tissue, as well as a larger field of view.

The teachings include a floating, multi-lumen-catheter retractor systemfor ease of positioning in a subject. These systems are designed toprovide a minimally invasive treatment of the subject. In someembodiments, the systems comprise a highly flexible outer tubeconfigured for guiding a floating channel and a floating endoscope in anat least substantially floating arrangement within the system. Thisflexible outer tube can have a lumen, a proximal end, and a distal end.And, during a use of the system, the floating channel can serve as aguide through which a tool is manipulated in a treatment of a targettissue in a subject. In some embodiments, the tool can include agrasper, a forcep, a snare, a clamp, a scissor, a knife, a dissector, anendoscopic stapler, a tissue loop, a clip applier, a suture-deliveringinstrument, or an energy-based tissue coagulator or cutter. And, in someembodiments, the floating channel can have an elevator component formoving a bendable section to manipulate the tool.

The system can also comprise a stable, yet dynamic operative environmentin that it can include a reversibly-expandable retractor that expands toform a treatment space in the subject. The retractor can be configured,for example, for the expansion to occur distal to the distal end of theouter tube and at least substantially render the target tissueaperistaltic for the treatment. During the use of the system, thefloating channel can be at least substantially attached to the lumen ofthe outer tube at a first proximal location and a first distal location,and be at least substantially floating in the lumen of the outer tubebetween the first proximal location and the first distal location.Likewise, during the use of the system, the floating endoscope can be atleast slidably-attached to the lumen of the outer tube at a secondproximal location and a second distal location, and be at leastsubstantially floating in the lumen of the outer tube between the secondproximal location and second distal location. And, during the use of thesystem, the at least substantially floating arrangement can at leastsubstantially increase the flexibility of the system over a second suchsystem, the second such system having a lumen for a tool and anendoscope affixed to the lumen throughout the length of the outer tubebetween the proximal end and the distal end of the outer tube. Theincreased flexibility of the at least substantially floating arrangementcan facilitate an ease of positioning the system in the subject for thetreatment of the target tissue.

In some embodiments, the retractor can be a reversibly-stabilized andreversibly-expandable retractor, retractor forming an asymmetricaltreatment space upon the expansion. And, the retractor can be configuredto reversibly stiffen an otherwise flexible arrangement of theretractor, the flexible arrangement designed to facilitate the ease ofpositioning of the system in the subject and to reversibly stiffen forthe expansion of the retractor.

The teachings also include a multi-lumen catheter system having areversibly-stabilized and reversibly-expandable retractor for aminimally invasive treatment of a subject. The system can comprise aflexible outer tube for guiding a channel and an endoscope within thesystem, the flexible outer tube having a lumen, a proximal end, and adistal end. The channel serves as a guide through which a tool ismanipulated in a treatment of a target tissue in a subject. In someembodiments, the retractor can be a reversibly-stabilized andreversibly-expandable retractor forming a treatment space upon expansionand configured for the expansion to occur distal to the distal end ofthe outer tube. The retractor can be designed to reversibly-stiffen anotherwise flexible arrangement of the retractor, the flexiblearrangement designed to facilitate the positioning of the system in thesubject and to reversibly stiffen for the expansion of the retractor. Inthese embodiments, the reversibly-stiffened arrangement of the retractorcan form an at least substantially rigid beam as a structural supportfor the expansion.

During a use of the system, the channel can be a floating channel thatis (i) at least substantially attached to the lumen of the outer tube ata first proximal location and a first distal location and (ii) at leastsubstantially floating in the lumen of the outer tube between the firstproximal location and the first distal location. Likewise, during theuse of the system, the endoscope can be a floating endoscope that is(iii) at least slidably-attached to the lumen of the outer tube at asecond proximal location and a second distal location and (iv) at leastsubstantially floating in the lumen of the outer tube between the secondproximal location and second distal location. And, during the use of thesystem, the channel and the endoscope form an at least substantiallyfloating arrangement that (v) at least substantially increases theflexibility of the system over a second such system having separatelumens for a tool and an endoscope, the separate lumens affixed to thelumen throughout the length of the outer tube between the proximal endand the distal end of the outer tube, the increased flexibilityfacilitating an ease of positioning the system in the subject for thetreatment of the target tissue.

The teachings also include a surgical suite with a floating,multi-lumen-catheter retractor system having a reversibly-stabilized andreversibly-expandable retractor for a minimally invasive treatment of asubject. In these embodiments, the system can comprise a highly flexibleouter tube for guiding a floating channel and a floating endoscope in anat least substantially floating arrangement within the system. Theflexible outer tube can have a lumen, a proximal end, and a distal end;and, the floating channel can serve as a guide through which a tool ismanipulated in a treatment of a target tissue in a subject. Theretractor can be a reversibly-stabilized and reversibly-expandableretractor forming a treatment space upon expansion. The retractor can beconfigured, for example, for the expansion to occur distal to the distalend of the outer tube and to reversibly stiffen an otherwise flexiblearrangement of the retractor, the flexible arrangement designed tofacilitate the positioning of the system in the subject and toreversibly stiffen for the expansion of the retractor.

During a use of the system, the floating channel can be (i) at leastslidably-attached to the lumen of the outer tube at a first proximallocation and a first distal location and (ii) at least substantiallyfloating in the lumen of the outer tube between the first proximallocation and the first distal location. Likewise, during the use of thesystem, the floating endoscope can be (iii) at least slidably-attachedto the lumen of the outer tube at a second proximal location and asecond distal location; and, (iv) at least substantially floating in thelumen of the outer tube between the second proximal location and seconddistal location. And, during the use of the system, the at leastsubstantially floating arrangement can (v) at least substantiallyincrease the flexibility of the system over a second such system havinglumens for a tool and an endoscope, the lumens affixed to the lumen ofthe outer tube throughout the length between the proximal end and thedistal end of the outer tube. The increased flexibility can facilitatean ease of positioning of the system in the subject; and, thereversibly-stiffened arrangement of the retractor can form an at leastsubstantially rigid beam as a structural support for the expansion inthe subject for the treatment of the target tissue.

In some embodiments, the retractor comprises at least two expandableretractor elements, each of the members having a proximal end and adistal end, the proximal end slidably engaged with the outer tube, andeach of the members configured such that an increase in the amount ofsliding of the proximal end toward the distal end compresses the memberand expands the retractor. These embodiments can also include a distalnexus located distal to the distal end of the outer tube and at whichthe distal end of each of the at least two retractor elements isaffixed; and, a stabilizer subsystem connecting the distal nexus to thedistal end of the outer tube and having an at least substantially rigidcomponent configured to reversibly stiffen an otherwise flexible portionof the retractor for an asymmetric expansion of the retractor.

In some embodiments, the retractor comprises four expandable retractorelements, each of the members having a proximal end and a distal end,the proximal end slidably engaged with the outer tube, and each of themembers configured such that an increase in the amount of sliding of theproximal end toward the distal end compresses the member and expands theretractor. These embodiments can also include a proximal couplerattached to the distal end of the outer tube, the proximal couplerhaving four retractor ports for the slidable engagement with the fourretractor elements, the four retractor ports positionedcircumferentially around the proximal coupler and configured tofacilitate a reversible, axial sliding of the retractor elements for theasymmetric expansion of the retractor. These embodiments can alsoinclude a distal nexus located distal to the distal end of the outertube and at which the distal ends of each of the four retractor elementsare affixed; and, a stabilizer subsystem connecting the distal nexus tothe distal end of the outer tube and having (i) a flexible componentthat extends from the proximal coupler to the distal nexus and (ii) anat least substantially rigid component that is slidably engaged with theproximal coupler and reversibly extends from the proximal coupler to thedistal nexus to reversibly-stiffen the retractor in an asymmetricexpansion of the retractor.

The flexible component and the rigid component can have central axesthat are each at least substantially parallel to the central axis of thedistal end of the shaft, the rigid component forming an at leastsubstantially rigid beam as a structural support for the asymmetricexpansion, the rigid beam having a luminal side and an abluminal side.And, the expansion can occur in a disproportionally greater amount onthe luminal side of the rigid beam to increase the treatment space, thetreatment space having a volume that is asymmetrically distributedaround the rigid beam. In some embodiments, the expansion can occur inan amount that is at least 5× greater on the luminal side of the beamthan the abluminal side of the beam.

In some embodiments, the system can include a bridge member configuredto maintain a desired orientation of the retractor elements during theexpansion, the bridge member operably stabilizing at least two of thefour retractor elements. Moreover, in some embodiments, the outer tubecan be wire-reinforced to provide kink resistance and torqueability tothe system to further facilitate a positioning of the system in thesubject.

The systems provided herein can be used in several different methods oftreatment. For example, the systems can be used in a method of treatinga gastrointestinal lesion using a multidirectional and multi-angularapproach to the lesion. The method can include positioning the system ina subject's gastrointestinal tract, the positioning including placingthe retractor in proximity to a target lesion for a treatment; expandingthe retractor to create the treatment space for use of the tool;improving visualization, for example, some lesions can be seen muchbetter when tissue is retracted and stabilized; optimally positioningthe target tissue in relation to the tool, for example, by optimizingthe position of the duodenal papilla, facilitating its cannulationduring a procedure; treating the target tissue with the tool; collapsingthe retractor; and, withdrawing the system from the subject. The lesioncan include, for example, a perforation, a tissue pathology a polyp, atumor, a bleed, a diverticuli, an ulcer, a cancerous tissue, an abnormalvessel, or an appendix.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a system for operatively treating gastrointestinaldisorders endoscopically in a stable, yet dynamic operative environment,and in a minimally-invasive manner, according to some embodiments.

FIGS. 2A and 2B illustrate how a system as taught herein can bepositioned for treating a lesion in the ascending colon, according tosome embodiments.

FIGS. 3A-3L illustrate how a system as taught herein can be used inremoving a lesion in a colon, according to some embodiments.

FIGS. 4A-4E illustrate details of a system as taught herein, in side,axial, and oblique views of expanded and collapsed configurations, andincluding a stabilizer subsystem, according to some embodiments.

FIGS. 5A-5D illustrate side and top views of a system as taught herein,having side views and top views of expanded and collapsedconfigurations, according to some embodiments.

FIGS. 6A-6D illustrate side views of a system as taught herein, havingside views and cross-sections of expanded and collapsed configurationsof the system, according to some embodiments.

FIG. 7 illustrates a cutaway view of the distal end of the outer tube ofa system as taught herein, showing components of the expansion andcollapse of the retractor, according to some embodiments.

FIG. 8 illustrates the cutaway view of FIG. 7, showing the distal end ofthe outer tube of a system as taught herein, in which components of thesystem can be floating in the outer tube to enhance flexibility forpositioning the system in a subject, according to some embodiments.

FIGS. 9A and 9B illustrate side views of working, and/or floating,channels that can be used to guide tools as taught herein, according tosome embodiments.

FIGS. 10A-10E illustrate a retractor sheath covering a retractor of asystem as taught herein, according to some embodiments.

DETAILED DESCRIPTION

The teachings provided herein are generally directed to improved methodsand devices for operatively treating gastrointestinal disordersendoscopically in a stable, yet dynamic operative environment, and in aminimally-invasive manner. The systems, for example, include anendoscopic surgical suite. The surgical suite can have areversibly-expandable retractor that expands to provide a stable,operative environment within a subject. In some embodiments, theexpansion can be asymmetric around a stabilizer subsystem to maximizespace for a tool and an endoscope to each be maneuvered independently tovisualize a target tissue and treat the target tissue from outside thepatient in a minimally invasive manner. Embodiments taught herein canprovide, among other improvements, an increase in distance between toolports and the target tissue to enhance the independent maneuverabilityand triangulation of each of the tools with respect to the targettissue. This increase in distance can also provide a way of obtaining alarger field of view. The systems taught herein, for example, can (i)enable a working space to be dynamically configured around the targettissue in tortuous body lumens and orifices such as the gastrointestinaltract using controls from outside the body; (ii) provide a flexible,passageway for multiple surgical tools and instruments, such asendoscope and graspers to be passed from outside the body towards thetarget tissues; (iii) organize and/or constrain tools in the workingspace; (iv) at least substantially immobilize and/or stabilize thetarget tissue and surrounding tissue for a treatment; and/or (v) enablecontrol over the geometry position, and orientation of the instrumentssuch as the grasper in the working space from outside the body.

The terms “treat,” “treatment”, and “treating” include, for example, thetherapeutic and/or prophylactic uses in the prevention of a disease ordisorder, inhibition of a disease or disorder, and/or amelioration ofsymptoms of disease or disorder. The term “subject” and “patient” can beused interchangeably and refer to an animal such as a mammal including,but not limited to, non-primates such as, for example, a cow, pig,horse, cat, dog, rat, and mouse; and, primates such as, for example, amonkey or a human.

In some embodiments, the systems taught herein can include dynamicallyreconfigurable, asymmetric retractor structures on the distal end of aflexible and torque-able multi-channel shaft having a handle that allowsfor control over both the stiffness and geometry of the working spaceformed by the expansion of the retractor. In some embodiments, theretractor can include a stabilizer subsystem having 2-8, 3-5, 4-6, orany range therein, flexible retractor elements. In some embodiments, theretractor elements can be aligned at least substantially parallel toeach other when fully collapsed for positioning in the patient. In someembodiments, the retractor elements are aligned on planes that arewithin about 5-30 degrees, about 10-25 degrees, about 15-20 degrees,about 15 degrees, or any range therein, of each other, in someembodiments. In some embodiments, the retractor elements form a framethat has a length ranging from about 4-12 cm. 6-10 cm, 7-9 cm, 5-11 cm,or any range therein. In some embodiments, the frame is about 8 cm long.In some embodiments, the retractor elements form a frame that has awidth ranging from about 1-5 cm. 2-4 cm, or any range therein. In someembodiments, the frame is about 3 cm wide. In some embodiments, theretractor elements form a frame that has a height ranging from about 1-5cm. 2-4 cm, or any range therein. In some embodiments, the frame isabout 3 cm high. One of skill will appreciate that there are a number ofsuitable materials that can be used to make the retractor elements forthe purposes set-forth herein. In some embodiments, the retractorelements can be made from NITINOL. In some embodiments, the retractorelement can comprise, multifilament steel wires or polymer cords. Thepolymer materials can include polyetheretherketone (PEEK), nylon,polyester, polycarbonate, polyurethane, or polyethylene. The gauge ofthe retractor elements can vary, depending on material. In someembodiments, the retractor elements can comprise wires that range fromabout 0.020″-0.40″ in diameter. In some embodiments, the retractorelements are 0.030″ in diameter.

The term “about” is used in the teachings herein to describe possiblevariations in amounts or ranges that can be used in embodiments. It canbe used in embodiments, for example, to include the exact amount orrange specified, as well as a variation of which that would not create asubstantial difference in function. A difference in function can beinsubstantial, for example, where it is less than 20% in someembodiments, less than 15% in other embodiments, less than 10% in yetother embodiments, or perhaps even less than 5% in yet otherembodiments. One of skill will appreciate that the percentage differencein function required for to be substantial will depend on the functionof the embodiment itself that is under comparison.

The methods, devices, and systems taught herein can be used forminimally-invasive procedures. A non-invasive procedure, in contrast,can be defined as a procedure that includes no violation of the skin orthe mucosa, and no appreciable damage to any other tissues of the body.A minimally-invasive surgical operation, on the other hand, involvesminimal access trauma and minimal collateral tissue damage during asurgical operation. The terms “minimal,” “minimize,” “minimizing,”“minimized,” “avoid,” “avoiding,” “avoided,” can be used interchangeablyin some embodiments. Minimally-invasive surgery is desirable, forexample, to reduce trauma to the patient, speed the healing process,reduce risk and, thus, reduce the length and expense of a hospital stayby minimizing or avoiding tissue damage, or risk of tissue damage.Tissue damage, or the risk thereof, can be minimized or avoided, forexample, where a procedure is designed to minimize or avoid unnecessarytissue contact that may otherwise be associated with a procedure. Thegentle procedures taught herein, for example, are directed to preservingtissue during a gastrointestinal surgery.

The systems taught herein can be dynamic in some embodiments, forexample, such that the tissue retraction can include partial or completeexpansion or collapse of a retractor to facilitate an increase ordecrease in the distance between instruments and the target tissue,which is useful in reconfiguring the work space and aiding in axialmovements of the tools. By increasing and releasing the tension, theamount of tissue to be placed in the working space can also bebetter-gauged during a procedure, for example, and tissuetraction-contra-traction can be facilitated to help in creating adissecting plane during a removal of tissue. One of skill willappreciate having the ability to dynamically reconfigure the workingspace and optimize traction-contraction on the target tissue, as thiscan facilitate surgical manipulations.

FIG. 1 illustrates a system for operatively treating gastrointestinaldisorders endoscopically in a stable, yet dynamic operative environment,and in a minimally-invasive manner, according to some embodiments. Thesystem 100 can include a multi-lumen-catheter retractor system for easeof positioning in a subject, and such systems can be designed to providea minimally invasive treatment of the subject. The system 100 can have aflexible outer tube 105 configured for guiding a channel 110 and anendoscope 115 within the system 100. The flexible outer tube 105 canhave a lumen (not shown), a proximal end (not shown), and a distal end(not shown) to house, for example, the channel and the endoscope duringuse of the system 100. As such, the outer tube can be a multi-luminaltube, in some embodiments. And, during the use of the system 100, thechannel 110 can serve as a guide through which a tool 120, 125 can bemanipulated in a treatment of a target tissue 190 in thegastrointestinal tract 195 of the subject. The channel 110 can, forexample, be in operable contact with an independentlymanipulable-and-articulable tool, the channel having an elevatorcomponent for moving a bendable section.

In some embodiments, the tool can be any tool known to one of skill. Forexample, the tool 120, 125 can include a grasper, a forcep, a snare, ascissor, a knife, a dissector, a clamp, an endoscopic stapler, a tissueloop, a clip applier, a suture-delivering instrument, or an energy-basedtissue coagulator or cutter. And, in some embodiments, the channel 110can have an elevator component (not shown) for moving a bendablesection, often a distal end of the channel 110, to manipulate the tool120, 125. In some embodiments, at least one channel 110 and/or theendoscope 115 can have at least substantial freedom to move within theouter tube 105 during operation, or “float,” such that the system 100can be considered to be a floating, multi-lumen-catheter retractorsystem. It should be appreciated that the terms “tool” and “instrument”can be used interchangeably in some embodiments taught herein.

In some embodiments, the system can comprise a stable, yet dynamicoperative environment in that it can include a reversibly-expandableretractor 150 that expands to form a treatment space 160 in the subject.The retractor 150 can be configured, for example, for the expansion tooccur distal to the distal end 108 of the outer tube 105. In someembodiments, the retractor can at least substantially render the targettissue 190 aperistaltic for the treatment. The retractor 150 can have avariety of configurations to serve, for example, as a scaffolding withinthe gastrointestinal tract 195. For example, the retractor 150 caninclude retractor elements 151, 152, 153, 154, along with a proximalcoupler 198 operably connected to the retractor elements 151, 152, 153,154, whether at least substantially attached and/or at leastslidably-engaged to the retractor elements 151, 152, 153, 154, and adistal nexus 199 for a distal point of an operable connection with theretractor elements 151, 152, 153, 154.

Moreover, the retractor 150 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 150 forming anasymmetrical treatment space 160 upon the expansion. And, the retractor150 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 150, the arrangement designed to facilitateease of positioning of the system 100 in the subject and to reversiblystiffen for the expansion of the retractor 150. The stabilization of theretractor 150 can, in some embodiments, include a means for stabilizingthe retractor 150 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 175to support the expanded retractor 150.

In some embodiments, the outer tube can have any dimensions believed tobe useful to one of skill for the purposes taught herein. For example,the outer tube can have an outer diameter ranging from about 3 mm toabout 30 mm, about 5 mm to about 25 mm, about 7 mm to about 22 mm, fromabout 9 mm to about 20 mm, from about 11 mm to about 18 mm, from about 8mm to about 15 mm, from about 10 mm to about 16 mm, or any range thereinin increments of 1 mm. The length of the outer tube can range, forexample, from about 30″ to about 72″, from about 31″ to about 36″, fromabout 28″ to about 80″, from about 32″ to about 40″, from about 34″ toabout 38″, or any range therein in increments of 1″.

The outer tube can be manufactured from any materials know to be usefulto one of skill for the purposes taught herein. For example, the outtube can comprise a polymer, or perhaps a polymer having an embeddedwire reinforcement. The wire reinforcement can be a mesh, a braid, ahelical coil or any combination thereof. The wire reinforcement caninclude any material believed by one of skill to be useful for thepurposes set-forth herein. For example, wire reinforcement can comprisea material having an elastic modulus that is about 1-3 orders ofmagnitude higher than the polymer tube. The wire material can comprise,for example, a stainless steel having a diameter ranging from about0.003″ to about 0.017″, about 0.005″ to about 0.015″, about 0.010″ toabout 0.012″, or any range therein in increments of about 0.001″. Thetube hardness, or durometer, can be any of that which one of skill willfind useful for the purposes set forth herein. For example, the hardnesscan range, for example, from about 50 Shore A to about 60 Shore A, about40 Shore A to about 80 Shore A, about 45 Shore A to about 70 Shore A, orany range therein in increments of 1 Shore A. One of skill willappreciate that the outer tube should be flexible, elastically bendable,but sufficiently stiff torsionally to transmit torque from the handle orproximal end of the system to the retractor or distal end of the system.

The outer tube can be connected to a ring distally, referred to hereinas the proximal coupler in some embodiments, which can have portals forretractor elements to slide through, as well as a desired orientationand positioning of the channels for the endoscope and at least one tool,such that the retractor elements, endoscope, and at least one tool areorganized relative to each other in a predetermined manner to achieve aparticular function, such as an increase in working space, a better viewof a plane of dissection, or any other procedural variable deemed ofinterest to one of skill.

In some embodiments, the retractor structures taught herein are each ameans for substantially immobilizing the lesion to the extent desiredfor the treatment. For example, the current use of loops and apiece-meal removal of flat or wide-based polyps, such as those having abase of about 1 cm or wider, may not provide clear surgical margins,whereas the systems taught herein can, in some embodiments, immobilizeor affix the entire circumference of the bowel wall around the treatmentarea and facilitate the production of clear surgical margins. One ofskill will appreciate having a working space that can be provided by thesystems taught herein, the working space being (i) at leastsubstantially non-collapsible, (ii) at least substantially aperistaltic;and, (iii) at least substantially affixed at a particular point in theabdominal cavity in relation to any fixed body point, like a hip, forexample. This is a significant improvement over existing systems, asexisting systems have not addressed many existing problems including,for example, bowel collapse that can result from an air leak from theworking space; peristalsis that is normal, even in a sedated patient;and, additional undesired bowel movements caused by the patient'sbreathing, movement of the scope or other instrument manipulation, orperhaps even by a surrounding peristalsis causing movement at atreatment area. Such problems are addressed by systems taught herein. Assuch, systems taught herein can offer a rigid, stable structure havingat least substantial resistance to a variety of moving forces in theabdomen that are typically present during a gastrointestinal endoscopicprocedure. One of skill will appreciate decreasing the effects of thesemoving forces on the working space to help reduce otherwise inherenttechnical complexities, limited efficacies, and decreased safety duringendoscopic procedures.

In some embodiments, the systems taught herein can be slidablypositioned over an endoscope during use. In fact, it should beappreciated that there are a variety of methods of using systems taughtherein that are already used by one of skill in current state-of-the-artprocedures. For example, the method can include inserting themulti-luminal tube into an overtube, cover, or sheath. And, in someembodiments, the endoscope can be a colonoscope. In many embodiments,regardless of the method of use, the retractor structures canmechanically retract one side of the colonic wall in an asymmetricmanner to increase the distance between the target lesion and theopposite wall, as well as between the lesion and the instruments intheir most retracted, but visualized, position to increase the effectivework space.

In some embodiments, the systems can include a multi-lumen catheterhaving at least 2 working channels for manipulating tools and anendoscope, each of the two working channels having 6 degrees of freedomthat are independent from each other and the endoscope. The ability toindependently manipulate the endoscope and tools allows, for example,one instrument to retract the tissue or lesion away or substantiallyperpendicular to another instrument, for example, the dissectinginstrument, while independently optimizing the endoscope's position and,hence, the view of the treatment area. This would facilitate the removalof tissue with clear margins. The channels can manipulate the tools withseveral degrees of freedom, 6 degrees of freedom in some embodiments,providing a greatly enhanced maneuverability in the working area whencompared to current state-of-the-art systems. In some embodiments, theat least one independently manipulable-and-articulable tool can beindependently rotatable to an angle of up to about 360 degrees, about315 degrees, about 270, about 225 degrees, about 180 degrees, about 135degrees, or about 90 degrees in the working area. In addition the toolscan be independently bendable to an angle of up to about 180 degrees,about 135 degrees, about 90 degrees, or about 45 degrees in at least onedirection in the working area.

The systems taught herein can have a means for organizing theorientation of the floating channels, in order to further facilitateimproving the flexibility of the system. In some embodiments, forexample, the proximal coupler, the ring that can be attached to thedistal end of the outer tube, can be used to organize the tools andendoscope in a particular arrangement to facilitate a particularpositioning of the tools as they emerge from the shaft into the workingspace created by the retractor. In some embodiments, the tool channelscan be placed further than the endoscope from the retractor elementsthat expand the most. Likewise, the proximal end of the outer tube canalso have respective openings for each of the channels, and theseopenings can be, for example, a part of a handle coupler, or the handleitself, operably connecting one or more of the channels to the outertube. The operable connection between the outer tube and channels canprovide a means for controlling the endoscope and tools, for example,from outside the patient. The rings can be made of any material believedby one of skill to be suitable for the purposes discussed herein. Forexample, the rings can be made of stainless steel, or perhaps a plasticsuch as polycarbonate or acrylonitrile butadiene styrene (ABS).

It should be appreciated that, in some embodiments, the systems taughtherein can include any combination of components, the selectedcombination of which is designed to be operable with components that areobtained separate from the system. For example, the system can includean outer tube and a retractor component, the outer tube being operablewith at least one channel obtained separately and an endoscope obtainedseparately. Likewise, the system can include an outer tube, a retractor,and an endoscope, and the channels are obtained separately; or an outertube, a retractor, and a channel, the endoscope obtained separately.Moreover, the system can include an outer tube, a retractor, anendoscope, and at least one channel; or, a handle, an outer tube, aretractor, an endoscope, at least one channel, and at least one tool.

The terms “substantial,” and “substantially” can be used, for example,to refer to a relative measure for a parameter. It can be used in someembodiments, for example, to refer to a degree of change or functionthat relates to an amount, a performance, or some other characteristic.The following are for purposes of example in describing generalembodiments: As described, the systems can be considered to be floatingsystems, can have a floating channel, a floating endoscope, multiplefloating channels, or a combination thereof, in some embodiments. Forexample, the phrase, “an at least substantially floating arrangementwithin the system”, can refer to an arrangement, for example a channelor endoscope arrangement, that can have some attachment that restrictsmovement in at least one direction, a minimal attachment to minimizesuch restriction of movement, or perhaps no attachment at all, toanother system component. For example, a channel or endoscope can bearranged to be at least substantially floating in the outer tuberelative to a second such system that does not use a floating-typearrangement to increase flexibility, or inherently achieve an increasein flexibility, of the second such system. As such, in many embodiments,the endoscope and/or channel can have a substantial portion of itsarrangement unattached within the system, allowing the substantialportion to “float” or move substantially freely within the outer tube.The “substantial portion” can be, for example, a percentage of thearrangement that must remain unattached within the system to provide aperformance characteristic, such as an increased flexibility of thesystem when compared to the second such system that does not use afloating-type arrangement to increase flexibility, or inherently achievean increase in flexibility, of the second such system.

The phrase, “at least substantially render the target tissueaperistaltic for the treatment”, for example, can refer to the targettissue having some minimal peristalsis, or perhaps no peristalsis, underthe conditions of normal use to provide a performance characteristic,such as controlling movement of the target tissue to facilitatetreatment. The phrase, “at least substantially attached”, for example,“at least substantially attached to the lumen of the outer tube”, forexample, can refer to a component having a fixed attachment or moveableattachment. In some embodiments, the attachment can be between thecomponent and the lumen, such that there is a loss of at least onedegree of freedom of movement of the component. For example, thecomponent can slide and/or rotate in relation to the lumen of the outertube, as long as the sliding and/or rotating occur in relation to aparticular fixed point on the lumen. Likewise, “at least substantiallyattached” can, of course, mean “fixed”, “reversibly fixed,” or the like,in some embodiments. Likewise, “at least slidably-attached” can refer toan attachment between components that allows for at least sliding motionbetween components such as, for example, a sliding motion between a portand a tube. In some embodiments, an endoscope can be at leastslidably-attached, for example, where the scope is allowed to slide inthe direction of the scope's central axis in and out of a port, suchthat the distance that the scope extends beyond the port is adjustable.And, in some embodiments, a component can be “at leastslidably-attached” where it can slide as well as move in otherdirections. For example, the port can be substantially larger than thescope, in some embodiments, such that the scope can slide axially, aswell as move side-to-side, align its central axis parallel to thecentral axis of the outer tube, or perhaps, misalign it's central axisto not be parallel to the central axis of the outer tube.

The phrase, “at least substantially increases the flexibility” can referto an orientation of components that enhances the flexibility of asystem when compared to another orientation and design of thecomponents. For example the phrase “at least substantially increases theflexibility of the system over a second such system” can refer to acomparison of flexibility of the claimed system over the second systemnot having the floating arrangement under the conditions of normal use,such that the flexibility of the system has increased to a minimalamount that improves the ease of positioning the system in the subjectfor the treatment of the target tissue.

The phrase, “at least substantially rigid component,” can refer acomponent that is rigid, or sufficiently rigid such that the desiredfunction is obtained, under the forces that are created with normal use.For example, a desired function may be to prevent or inhibit theoccurrence of a bending moment of the rigid component at one or morepoints along the length of a retractor upon expansion of the retractorin the subject. In some embodiments, the systems taught herein can havea retractor with four retractor elements, at least two of which areexpandable in the subject to create a working space for a treatment. Inthis example, the expansion of the at least two retractor elementstoward the target tissue to create the working space requires a forcesufficient to retract the tissue and, creates an opposing force in theopposite direction that can create the bending moment in the rigidcomponent. One of skill should appreciate that such a bending moment canbe problematic, for example, where it contributes to an instability thataffects the user's control over the position of the retractor during atreatment of the target tissue. In such embodiments, a component thatprevents or inhibits the bending moment can be “at least substantiallyrigid,” for example, where the user retains a desired level of control,or at least sufficient control, over the position of the retractorduring the retraction of the target tissue. In some embodiments, acomponent that prevents or inhibits a bending moment, whether in or outof the subject, can be at least substantially rigid where the bending ofthe component due to the expansion of the retractor creates a deflectionthat ranges from 0.0 to about 5 degrees, about 1.0 degree to about 10degrees, about 2.0 degrees to about 12 degrees, about 3.0 degree toabout 10 degrees, about 1.0 degree to about 15 degrees, about 1.0 degreeto about 9.0 degrees, about 1.0 degree to about 8.0 degrees, about 1.0degree to about 7.0 degrees, about 1.0 degree to about 6.0 degrees,about 1.0 degree to about 5.0 degrees, about 1.0 degree to about 4.0degrees, or any range therein in increments of about 0.1 degree. In someembodiments, the deflection of the rigid component cannot exceed about1.0 degree, about 2.0 degrees, about 3.0 degrees, about 4.0 degrees,about 5.0 degrees, about 6.0 degrees, about 7.0 degrees, about 8.0degrees, about 9.0 degrees, about 10.0 degrees, or any 0.1 degreeincrement therein. The bending can be measured, for example, as a pointof deflection from the original position of the rigid component's axisfrom force created on the rigid component through the expansion.

The terms “substantial” or “substantially” can be used interchangeablyin some embodiments, and can be described using any relative measuresacceptable by one of skill. For example, relative percentages can beused to indicate a substantial amount, substantial change, substantialdifference, substantial function, or the like. In some embodiments, thepercentage can be greater than 10%, greater than 20%, greater than 30%,greater than 40%, or greater than 50%. In some embodiments, thepercentage can be greater than 60%, greater than 70%, or greater than80%. And, in some embodiments, the percentage can be greater than 90%,greater than 95%, or in some embodiments, even greater than 99%. Forexample, a substantial [amount]” or a “substantial [change]”, caninclude any amount or change relative to a reference parameter. Theamount or change, for example, can include an increase or decreaserelative to the reference parameter, can be compared to a referencepoint for the parameter. The deviation from the reference point can be,for example, in an amount of at least 1%, at least 2%, at least 3%, atleast 5%, at least 10%, at least 15%, at least 20%, at least 25%, atleast 30%, at least 35%, at least 40%, at least 45%, or any 1% incrementtherein. Also, for example, a “substantial [function]” or “substantially[functioning]” limitation can serve as a comparison to a referencefunction parameter, to indicate a deviation that will still provide theintended function. Reference functions can include, for example,floating, aperistalsis, attaching, flexing, rigidity, a position orpositioning relative to another object, and the like. The deviation fromthe reference point can be, for example, in an amount of less than 1%,less than 3%, less than 5%, less than 10%, less than 15%, less than 20%,less than 25%, less than 30%, less than 35%, less than 40%, less than45%, or any 0.1% increment therein. For example, a component can have anacceptable, substantial [function] when it deviates from the referenceby less than the acceptable deviation.

As such, the system can include a floating, multi-lumen-catheterretractor system for ease of positioning in a subject, and such systemscan be designed to provide a minimally invasive treatment of thesubject. In some embodiments, the systems comprise a highly flexibleouter tube configured for guiding a floating channel and a floatingendoscope in an at least substantially floating arrangement within thesystem. This flexible outer tube can have a lumen, a proximal end, and adistal end. And, during a use of the system, the floating channel canserve as a guide through which a tool is manipulated in a treatment of atarget tissue in a subject. In some embodiments, the tool can include agrasper, a forcep, a scissor, a knife, a dissector, an endoscopicstapler, a tissue loop, a clip applier, a suture-delivering instrument,or an energy-based tissue coagulator or cutter. And, in someembodiments, the floating channel can have an elevator component formoving a bendable section to manipulate the tool. In some embodiments,at least one channel and/or the endoscope can have at least substantialfreedom to move within the outer tube during operation, or “float,” suchthat the system can be considered to be a floating, multi-lumen-catheterretractor system as taught herein.

Likewise, the system can also comprise a stable, yet dynamic operativeenvironment in that it can include a reversibly-expandable retractorthat expands to form a treatment space in the subject. The retractor canbe configured, for example, for the expansion to occur distal to thedistal end of the outer tube and at least substantially render thetarget tissue aperistaltic for the treatment; wherein, during a use ofthe system in a subject, the floating channel can be at leastsubstantially attached to the lumen of the outer tube at a firstproximal location and a first distal location, and be at leastsubstantially floating in the lumen of the outer tube between the firstproximal location and the first distal location. Likewise, during theuse of the system, the floating endoscope can be at leastslidably-attached to the lumen of the outer tube at a second proximallocation and a second distal location, and be at least substantiallyfloating in the lumen of the outer tube between the second proximallocation and second distal location. And, during the use of the system,the at least substantially floating arrangement can at leastsubstantially increase the flexibility of the system over a second suchsystem, the second such system having a lumen for a tool and anendoscope affixed to the lumen throughout the length of the outer tubebetween the proximal end and the distal end of the outer tube. Theincreased flexibility of the at least substantially floating arrangementcan facilitate an ease of positioning the system in the subject for thetreatment of the target tissue. Moreover, the retractor can be areversibly-stabilized and reversibly-expandable retractor, retractorforming an asymmetrical treatment space upon the expansion. And, theretractor can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor, the flexible arrangement designed tofacilitate the ease of positioning of the system in the subject and toreversibly stiffen for the expansion of the retractor.

FIGS. 2A and 2B illustrate how a system as taught herein can bepositioned for treating a lesion in the ascending colon, according tosome embodiments. It should be appreciated that any series of steps andmethods known to one of skill to be useful in the positioning 200 can beused with systems taught herein. FIG. 2A illustrates how an endoscope215 can be used to locate the lesion, a target tissue 290 in a portionof the ascending colon 295. FIG. 2B illustrates how themulti-lumen-catheter retractor system 201 can be guided to the targettissue 290 using the endoscope 215 as a guide for the positioning 200 ofthe system in the treatment of the target tissue 290.

FIGS. 3A-3L illustrate how a system as taught herein can be used inremoving a lesion in a colon, according to some embodiments. The systemcan be positioned as in FIGS. 2A and 2B in the treatment 300 of agastrointestinal lesion 390, and a multidirectional and multi-angularapproach to the lesion can be used. As in FIGS. 2A and 2B, for example,the approach can include identifying a lesion in a gastrointestinallumen of a subject using an endoscope 315; and, forming a substantiallyrigid and stable endoluminal working area for treating a target tissue,the gastrointestinal lesion 390. In FIG. 3A, the system is positioned atthe lesion 390, and in FIG. 3B, the expandable retractor 350 expands tocreate an asymmetrical working space 360.

FIGS. 3C and 3D illustrate the creation of the working space 360, andmanipulation of the endoscope 315 and tools 320, 325. After positioningthe retractor 350 in proximity to the lesion 390, the retractor 350 isexpanded to form the asymmetrical working space 360 for the treating ofthe lesion 390. The system can have any configuration taught herein,such as (i) at least one independently manipulable-and-articulable scope315 to be used in viewing the lesion 390, (ii) at least one tool channel310 for at least one independently manipulable-and-articulable tool 320,325 to be used in the treating of the lesion 390, and (iii) theretractor 350, which can be an asymmetrically expandable structure. Insome embodiments, the retractor 350 can be expanded asymmetricallytoward the lesion 390, the expanding including a portion of theretractor 350 pushing on tissue surrounding the lesion 390 to increasethe working area by providing an asymmetrical working area and thusfacilitate an entry of the lesion 390 into the working area 360 for thetreating. The retractor 350 can be located distal to the distal end ofthe outer tube 305 and the asymmetrical working area 360 can besubstantially rigid and stable relative to the independentlymanipulable-and-articulable scope 315 and the at least one tool 320, 325to facilitate treating the lesion 390. The treating of the lesion 390can include, for example, (i) viewing the lesion 390 with thearticulating scope 315 and (ii) using the at least one tool 320, 325 inthe treatment of the lesion 390 with a multidirectional andmulti-angular approach to the lesion 390 in the asymmetrical workingarea 360.

In some embodiments, the independently manipulable-and-articulable scope315 and the at least one tool 320, 325 can be independently movableaxially in the working area 360, independently rotatable in the workingarea 360, and independently bendable in at least one direction in theworking area 360. Accordingly, in some embodiments, the portion of theretractor 350 pushing on the tissue surrounding the lesion 390 can beexpanded further from the central axis 307 of the distal end of theouter tube 305 than other portions of the retractor to provide an evenlarger working area 360 for the treating of the lesion 390 when comparedto a second such structure that merely expands symmetrically around thecentral axis 307 of the distal end of the outer tube 305.

FIG. 3E illustrates a multidirectional and multi-angular approach to thelesion 390, showing the step of positioning the work area 360, endoscope315, and tools 320, 325 in relation to the lesion 390. After theretractor 350 is expanded, the user of the system can view and approachthe lesion 390 with the tools 320, 325 from nearly any desired anglewithin the working space 360. FIG. 3F illustrates the versatility of thesystem, showing the step of removing the lesion 390 using tool 320 toexcise the lesion 390 from an independently chosen first angle, whiletool 325 can be used to grasp the lesion 390 from an independentlychosen second angle and endoscope 315 can be used to view the lesion 390from an independently chosen third angle. After the excision of thelesion 390 from the gastrointestinal tract 395, a tissue defect 397remains. FIG. 3G illustrates the step of releasing the excised lesion390 into the retractor assembly in preparation for completion of theprocedure. FIGS. 3H and 31 illustrate the step of closing the tissuedefect 397, showing that tool 320 for excision of the lesion 390 hasbeen replaced by tool 322 for closure of the lesion. FIGS. 3J and 3Killustrate the steps of capturing the lesion 390 for removal using tool323 and collapsing the retractor 350 in preparation for removal of thesystem from the subject, including the use of an optional retractorcover 355. FIG. 3L is a view of the closed tissue defect followingcompletion of the treatment.

In some embodiments, as shown for example in FIGS. 3B-3J, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 350 that expands to form atreatment space 360 in the subject. The retractor 350 can be configured,for example, for the expansion to occur distal to the distal end 308 ofthe outer tube 305. In some embodiments, the retractor can at leastsubstantially render the target tissue 390 aperistaltic for thetreatment. The retractor 350 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract395. For example, the retractor 350 can include retractor elements 351,352, 353, 354, along with a proximal coupler 398 operably connected tothe retractor elements 351, 352, 353, 354, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 351, 352, 353, 354, and a distal nexus 399 for a distal pointof an operable connection with the retractor elements 351, 352, 353,354. The distal nexus 399 is shown in the shape of a ring, although itcan be virtually any shape desirable to one of skill, such as a cone,hemisphere, sphere, and the like, and it may or may not include a portfor passage of the endoscope beyond the distal end of the system.

Moreover, the retractor 350 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 350 forming anasymmetrical treatment space 360 upon the expansion. And, the retractor350 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 350, the arrangement designed to facilitateease of positioning of the system 300 in the subject and to reversiblystiffen for the expansion of the retractor 350. The stabilization of theretractor 350 can, in some embodiments, include a means for stabilizingthe retractor 350 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 375to support the expanded retractor 350.

FIGS. 4A-4E illustrate details of a system as taught herein, in side,axial, and oblique views of expanded and collapsed configurations, andincluding a stabilizer subsystem, according to some embodiments. Thefigures illustrate an example of a multi-lumen catheter system having areversibly-stabilized and reversibly-expandable retractor for aminimally invasive treatment of a subject. FIGS. 4A-4C illustrate sideand axial views that show that the system 400 can comprise a flexibleouter tube 405 for guiding a channel (not shown) and an endoscope (notshown) within the system 400. The flexible outer tube 405 has a lumen, aproximal end (not shown), and a distal end 408. The channel (not shown)serves as a guide through which a tool (not shown) can be manipulated ina treatment of a target tissue in a subject. In some embodiments, theretractor 450 can be a reversibly-stabilized and reversibly-expandableretractor 450 forming a treatment space upon expansion and configuredfor the expansion to occur distal to the distal end 408 of the outertube 405. The retractor 450 can be designed to reversibly-stiffen anotherwise flexible arrangement of the retractor 450, the flexiblearrangement designed to facilitate the positioning of the system in thesubject and to reversibly-stiffen for the expansion of the retractor450. In these embodiments, the reversibly-stiffened arrangement of theretractor 450 can form an at least substantially-rigid beam 475 from anotherwise flexible beam 470 as a structural support for the expansion ofthe retractor 450. In some embodiments, the stabilizer subsystem caninclude the flexible beam 470, which may comprise a flexible tube, and ameans for creating the at least substantially-rigid beam 475. The means,as taught herein, can include all embodiments taught herein, includingthe mechanisms for slidably-engaging an at least substantially-rigid rodor beam, for example, within the flexible rod or beam 470 prior toexpanding the retractor. In some embodiments, the terms “rod” and “beam”can be used interchangeably and, in some embodiments, the terms “beam”and “tube” can be used interchangeably.

In some embodiments, the flexible beams taught herein can comprise apolymer, such as polyimide, polyether block amides (PEBAX), nylon,polyethylene, polyurethane, polyvinylchloride (PVC), PEEK, orpolytetrafluoroethylene (TEFLON). One of skill will appreciate that theflexible beams can be reinforced tubes made from components and designsknown to the art. The flexible beam can be, for example, a flexible tubethat is reinforced with metal wires, braids, or coils that include, forexample, a metal such as a stainless steel or NITINOL. In someembodiments, the flexible tube can be kink resistant and transmittorque. And, in some embodiments, the flexible tube can comprise acombination of both flexible sections and rigid sections. In theseembodiments, a flexible section can lie-between rigid sections, forexample. Such flexible tubes can include composites of overlapping tubesjoined using any method known to one of skill, including bonding usingepoxy or cyanoacrylates, in some embodiments.

In some embodiments, any of the systems taught herein can include abridge member to add stability to the retractor. For example, bridgemember 444 is configured to maintain a desired orientation of theretractor elements 451, 452, 453, 454 during the expansion, the bridgemember 444 operably stabilizing at least two 451, 452 of the fourretractor elements 451, 452, 453, 454. Moreover, in some embodiments,each of the systems taught herein can have an outer tube that iswire-reinforced, such as mesh, braided, or the like, to provide kinkresistance and torqueability to the system, as well as to furtherfacilitate a positioning of the system in the subject.

FIGS. 4D and 4E illustrate oblique views of the system 400 in collapsedand expanded configurations. The multi-lumen concept is presented withclarity in these figures, showing multiple lumens 406 a, 406 b, 406 c inthe system 400. Lumen 406 a can contain an endoscope (not shown), lumen406 b can contain a first working channel 410 b for a first tool (notshown), and lumen 406 c can contain a second working channel 410 c for asecond tool (not shown). FIG. 4D in the collapsed configuration has aflexible beam 470, whereas FIG. 4E in the expanded configuration has arigid beam 475 that was formed from the flexible beam. A rigid beam canbe formed from a flexible beam, in some embodiments, by slidablyinserting a rigid rod into a flexible tube that composes the flexiblebeam. In many embodiments, the term “tool channel” can be usedinterchangeably with the term “working channel.” And, in someembodiments, a channel can be a separate component placed inside theouter tube, or it can be a space remaining in the lumen of the outertube between separate components that were placed in the outer tube, theseparate components including, for example, an endoscope, a workingchannel, an instrument, a guide, and the like.

In some embodiments, as shown for example in FIGS. 4A-4E, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 450 that expands to form atreatment space 460 in the subject. The retractor 450 can be configured,for example, for the expansion to occur distal to the distal end 408 ofthe outer tube 405. In some embodiments, the retractor can at leastsubstantially render the target tissue 490 aperistaltic for thetreatment. The retractor 450 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract495. For example, the retractor 450 can include retractor elements 451,452, 453, 454, along with a proximal coupler 498 operably connected tothe retractor elements 451, 452, 453, 454, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 451, 452, 453, 454, and a distal nexus 499 for a distal pointof an operable connection with the retractor elements 451, 452, 453,454.

Moreover, the retractor 450 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 450 forming anasymmetrical treatment space 460 upon the expansion. And, the retractor450 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 450, the arrangement designed to facilitateease of positioning of the system 400 in the subject and to reversiblystiffen for the expansion of the retractor 450. The stabilization of theretractor 450 can, in some embodiments, include a means for stabilizingthe retractor 450 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 475to support the expanded retractor 450.

FIGS. 5A-5D illustrate side and top views of a system as taught herein,having side views and top views of expanded and collapsedconfigurations, according to some embodiments. FIGS. 5A and 5Billustrates side views of system 500 in collapsed and expandedconfigurations showing an example of an asymmetric work space that canbe formed during an endoscopic procedure using the system 500. And, asshown in FIG. 5B, the expansion can occur in a disproportionally greateramount on the luminal side 559 of the rigid beam 575 than the abluminalside 557 of the rigid beam 575 to increase the treatment, or working,space 560, the treatment space 560 having a volume that isasymmetrically distributed around the rigid beam 575. In someembodiments, the expansion can occur in an amount that is at least 5×greater on the luminal side 559 of the rigid beam 575 than the abluminalside 557 of the rigid beam 575. And in some embodiments, the expansioncan be at least 1.1× greater, at least 1.3× greater, at least 1.5×greater, at least 2.0× greater, at least 2.5× greater, at least 3.0×greater, at least 3.5× greater, at least 4.0× greater, at least 4.5×greater, at least 5.0× greater, at least 5.5× greater, at least 6.0×greater, at least 6.5× greater, at least 7.0× greater, at least 7.5×greater, at least 8.0× greater, at least 8.5× greater, at least 9.0×greater, at least 9.5× greater, at least 10.0× greater, or any 0.1×increment within this range, on the luminal side of the beam than theabluminal side of the beam.

In some embodiments, as shown for example in FIGS. 5A-5D, the system cancomprise a stable, yet dynamic operative environment in that it caninclude a reversibly-expandable retractor 550 that expands to form atreatment space 560 in the subject. The retractor 550 can be configured,for example, for the expansion to occur distal to the distal end 508 ofthe outer tube 505. In some embodiments, the retractor can at leastsubstantially render the target tissue 590 aperistaltic for thetreatment. The retractor 550 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract595. For example, the retractor 550 can include retractor elements 551,552, 553, 554, along with a proximal coupler 598 operably connected tothe retractor elements 551, 552, 553, 554, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 551, 552, 553, 554, and a distal nexus 599 for a distal pointof an operable connection with the retractor elements 551, 552, 553,554.

Moreover, the retractor 550 can be a reversibly-stabilized andreversibly-expandable retractor, the retractor 550 forming anasymmetrical treatment space 560 upon the expansion. And, the retractor550 can be configured to reversibly stiffen an otherwise flexiblearrangement of the retractor 550, the arrangement designed to facilitateease of positioning of the system 500 in the subject and to reversiblystiffen for the expansion of the retractor 550. The stabilization of theretractor 550 can, in some embodiments, include a means for stabilizingthe retractor 550 through a stabilizer subsystem as taught herein, thestabilizer having, for example, an at least substantially-rigid beam 575to support the expanded retractor 550.

FIGS. 6A-6D illustrate side views of a system as taught herein havingside views and cross-sections of expanded and collapsed configurationsof the system, according to some embodiments. The figures illustrate anexample of a multi-lumen catheter system having a reversibly-stabilizedand reversibly-expandable retractor for a minimally invasive treatmentof a subject. FIGS. 6A and 6B illustrates a side view that shows thatthe system 600 can comprise a flexible outer tube 605 for guiding achannel (not shown) and an endoscope (not shown) within the system 600.The flexible outer tube 605 has a lumen, a proximal end (not shown), anda distal end 608. The channel (not shown) serves as a guide throughwhich a tool (not shown) can be manipulated in a treatment of a targettissue in a subject. In some embodiments, the retractor 650 can be areversibly-stabilized and reversibly-expandable retractor 650 forming atreatment space 660 upon expansion and configured for the expansion tooccur distal to the distal end 608 of the outer tube 605. The retractor650 can be designed to reversibly-stiffen an otherwise flexiblearrangement of the retractor 650, the flexible arrangement designed tofacilitate the positioning of the system in the subject and toreversibly-stiffen for the expansion of the retractor 650. In theseembodiments, the reversibly-stiffened arrangement of the retractor 650can form an at least substantially-rigid beam 675 from an otherwiseflexible beam 670 as a structural support for the expansion of theretractor 650.

Handle 680 includes entry ports for operatively combining the systemwith external components, such as an entry port 609 for an endoscope(not shown) and/or a tool (not shown). The handle is also operativelyconnected to the proximal end of the outer tube 605 and can have exitports from the handle 680 into the outer tube 605. The system caninclude a stabilizer subsystem, in some embodiments. For example, astabilizer actuator 612 can be included on the handle 680 toreversibly-stiffen the flexible beam 670 to create the at leastsubstantially-rigid beam 675 for the expansion of the retractor 650. Aretractor actuator 614 can be included on the handle 680 to reversiblyexpand the retractor 650.

FIGS. 6D and 6E illustrate oblique views of the system 600 in expandedconfigurations. The expanded configurations have a rigid beam 675 thatwas formed from the flexible beam that is typically present in thecollapsed state for positioning in the subject. The rigid beam 675 canbe formed from a flexible beam, in some embodiments, by slidablyinserting a rigid rod into a flexible tube that composes the flexiblebeam. As shown in FIGS. 6B and 6D, the stabilizer actuator 612 isoperably connected to the rigid rod 672 through a rod coupler 613.Likewise, the retractor actuator 614 is operably connected to aretractor element 651, 652 through an element coupler 611. Thestabilizer actuator 612 and/or the retractor actuator 614 can bereversibly engageable with the handle 680, in some embodiments, suchthat the stabilizer actuator 612 and/or the retractor actuator 614 canbe reversibly—fixed in position relative to the handle 680. In someembodiments, the stabilizer actuator 612 and/or the retractor actuator614 can be multi-positional, having at least three positions forexpansion and/or collapse of the retractor. In some embodiments, thestabilizer actuator 612 and/or the retractor actuator 614 can have aplurality of ratchet teeth 616 to provide a plurality of positions forreversibly-fixing the retractor in position during expansion or collapseof the retractor.

One of skill will appreciate that the handle can be any of a variety ofshapes to provide a desired or ergonomic position for operation of thesystem. By way of example, the retractor actuator can be configured as afinger-activated button on the handle 680 that slides back and forththrough a slot in the handle 680 to expand or collapse the retractorelements. A means for dynamically adjusting or ratcheting the retractorposition can be provided along the handle slot to lock the position ofthe retractor elements in place when the retractor actuator button isnot pressed. A button on the opposite side of the handle can beoperatively connected to the stabilizer subsystem to convert theflexible beam into a rigid beam, or convert the rigid beam into aflexible beam. The handle can have inner channels routed axially, forexample, within the body of the handle and in communication with portsfor tools and endoscope introduction into the outer tube. In someembodiments, the handle can be configured to require that the stabilizeractuator is activated before the retractor actuator can be activated,serving as a “safety” mechanism in the operation of the system.

As such, in some embodiments, as shown for example in FIGS. 6A-6D, thesystem can comprise a stable, yet dynamic operative environment in thatit can include a reversibly-expandable retractor 650 that expands toform a treatment space 660 in the subject. The retractor 650 can beconfigured, for example, for the expansion to occur distal to the distalend 608 of the outer tube 605. In some embodiments, the retractor can atleast substantially render the target tissue 690 aperistaltic for thetreatment. The retractor 650 can have a variety of configurations toserve, for example, as a scaffolding within the gastrointestinal tract695. For example, the retractor 650 can include retractor elements 651,652, 653, 654, along with a proximal coupler 698 operably connected tothe retractor elements 651, 652, 653, 654, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 651, 652, 653, 654, and a distal nexus 699 for a distal pointof an operable connection with the retractor elements 651, 652, 653,654.

Moreover, as described herein, the retractor 650 can be areversibly-stabilized and reversibly-expandable retractor, the retractor650 forming an asymmetrical treatment space 660 upon the expansion. And,the retractor 650 can be configured to reversibly stiffen an otherwiseflexible arrangement of the retractor 650, the arrangement designed tofacilitate ease of positioning of the system 600 in the subject and toreversibly stiffen for the expansion of the retractor 650. Thestabilization of the retractor 650 can, in some embodiments, include ameans for stabilizing the retractor 650 through a stabilizer subsystemas taught herein, the stabilizer having, for example, an at leastsubstantially-rigid beam 675 to support the expanded retractor 650.

The rigid rod can be a straight component comprising a rigid material,for example stainless steel or another metal or alloy, that isslide-able in and out of the inner diameter of the flexible tube. Assuch, the stabilizer subsystem can have a flexible beam or rigid beam bysliding the rigid rod proximal (i.e., anally) to the flexible tube bypulling back on the rigid rod through a mechanism operably connected tothe handle. The rigid rod can be pushed forward (i.e., orally) into theflexible tube to stiffen and straighten the flexible tube. By pushingthe rigid rod across the length of the flexible tube, the flexible tube,or flexible beam, becomes rigid and straight, and in effect renders thewhole retractor structure at least substantially rigid and straight. Oneof skill in the art will appreciate that any mechanism of reversiblystiffening a flexible component in vivo may be used in some embodiments.For example, the flexible tube, or flexible beam, may also comprise aseries of rigid tubes having a flexible, non-stretchable cable passingthrough the lumens of the tubes. When the cable is relaxed, the seriesof rigid tubes can be separated using, for example, a compressiblecomponent such as a spring between each of the series of rigid tubes toprovide a flexible non-overlapping configuration. When the cable istensioned, the compressible components compress, and the rigid tubesoverlap, converting the flexible beam into a rigid beam.

The reversibly-stabilized retractor, as described herein, is useful inpositioning the working space at the site of treatment of the targettissue as it can be rendered flexible for positioning and later renderedrigid for expansion of the retractor. During introduction of a systemtaught herein into a tortuous body lumen, for example a colon, theretractor can be unexpanded and flexible. This flexibility allows theretractor to bend to conform to the bends in the tortuous body lumen, sothat it can be advanced with ease and not cause trauma to the lumen. Therings which hold the retractor elements together can also have lumensthat allow passage of a guide such as an endoscope. In such embodiments,when the retractor is in the flexible mode for introduction, forexample, the rings can be free to slide over the guide as the system isadvanced forward. In some embodiments, the lumens of the rings can belarge enough relative to the diameter of the guide to allow for tiltingand translation of the system on the guide, helping the system conformto the bends of the guide during advancement of the system orally oranally. Once the retractor is advanced to the target location in thelumen, the flexible beam of the retractor can be straightened andstiffened as described herein. Since the system can be flexible andtorsionally stiff, the proximal shaft or the handle can be easilyrotated as desired relative to the location of the target lesion.

The retractor elements can have at least one pair that is pre-shapedhaving peaks pointing outwards at a desired angle. In some embodiments,the angle can range from about 45 degrees to about 135 degrees, about 60degrees to about 120 degrees from each other on one side of the rigidbeam, the vertex of the angle being the central axis of the rigid beam,as can be seen in the figures provided herein. In some embodiments, theangle is about 90 degrees between retractor elements. Upon expansion,the retractor elements bulge outwards on one side disproportionally morethan the other retractor elements, resulting in an asymmetricalexpansion of the retractor. The at least substantially rigid beamprevents or inhibits deformation of the retractor during creation offorces on the retractor in the expansion. The forces include forces fromexpanding tissue outwards asymmetrically, as well as the initial forcesapplied on the retractor elements to create an asymmetrical workingspace.

In some embodiments, the target lesion can be located on the side of themost expanded retractor elements so to facilitate maximizing orincreasing the distance between the lesion to be treated and the portalsat which the endoscope and tools are introduced into the working space.The endoscope and tools can be maneuvered independently, for example, toaccess the lesion at a greater range of angles than is currentlyclinically obtainable using state-of-the-art systems. This increasedmaneuverability can improve the view of the lesion and ability tomanipulate and dissect the lesion. For example, a grasper can beadvanced out of the instrument channel into the working space and flexedtowards the polyp, grasp the polyp and retract the tissue to expose thebase of the polyp for dissection by a dissection tool through themulti-channel systems taught herein. Sometimes, it can also be desiredto reduce the distance between the lesion to be treated and the portalsat which the endoscope and tools are introduced into the working space.For example, it can be desired to locate the lesion on the side of theleast expanded retractor elements to better align the lesion with theendoscope channel substantially parallel to the lumen wall. Such aconfiguration may be clinically optimal while the polyp is retracted bya grasper towards the most expanded side. In such embodiments, adissection tool can be advanced through a channel at the base of thepolyp and dissect the polyp's base where it attaches to the lumen wall,while the position of the endoscope provides a close view of the base ofthe polyp to help identify the desired margin for dissection.

In some embodiments, any of the systems taught herein can include abridge member, which provides structural support to add stability to theretractor. The bridge member can include any configuration conceivableby one of skill to provide additional support, such as a scaffoldingmeans, for enhancing or buttressing the stability and rigidity of theexpanded contractor. For example, bridge member 644 is configured tomaintain a desired orientation of the retractor elements 651, 652, 653,654 during the expansion, the bridge member 644 operably stabilizing atleast two 651, 652 of the four retractor elements 651, 652, 653, 654.Moreover, in some embodiments, each of the systems taught herein canhave an outer tube, for example outer tube 605, that is wire-reinforced,such as mesh, braided, or the like, to provide kink resistance andtorqueability to the system, as well as to further facilitate apositioning of the system in the subject. In some embodiments, thebridge member 644 can be configured to reduce drag from surroundingtissue during use. For example, as shown in FIGS. 6A and 6B, the bridgemember 644 can be configured to facilitate a movement of the system in agastrointestinal tract by designing the bridge member 644 to include aforward component 644 a that is inclined to facilitate forward movementorally, and a reverse component 644 b that is inclined to facilitatereverse movement anally.

The bridge member can be connected to the retractor elements, forexample, to maintain a desired orientation of the retractor elements asthey expand against a gastrointestinal tissue, for example. As theretractor is expanded, the bridge member is also expanded outward. Insome embodiments, the bridge member is operably connected only to theretractor elements that expand the most, for example the retractorelements 751, 752 in FIG. 7, which can be the members that incur themost induced forces on the retractor due to the disproportionatepressure applied to create the asymmetrical working space in theexpansion. In some embodiments, the bridge can be designed to flex toprevent the retractor elements from collapsing towards each other orbending away from each other, while also providing some spring orelasticity to the system to comply gently with the tissue. One of skillwill appreciate that the bridge can comprise any suitable material thatprovides the material characteristics desired. For example, the bridgecan be formed from a curved nitinol wire in some embodiments. The endsof the nitinol wires can be connected to the retractor elements usingany manufacturing process deemed suitable by one of skill for the invivo uses taught herein, such process including, for example, tubingconnectors, adhesives, or solder.

FIG. 7 illustrates a cutaway view of the distal end of the outer tube ofa system as taught herein, showing components of the expansion andcollapse of the retractor, according to some embodiments. The figureillustrates the distal end 708 of outer tube 705. The distal end 708includes a slot guide 755 to control the orientation of an expandingretractor element 751, as well as a port 754 a for operablyreceiving/supporting a lower retractor element 754. Likewise, a lumen706 c can be provided to contain a working channel 710 c. The lumen 706of the outer tube 705 can also be used to guide an endoscope (not shown)through port 706 a. Only a portion 751, 754, 770, 772, 775 of theretractor components is shown to partially describe the relation betweenthe outer tube 705 and the retractor in some embodiments. The retractorcan be configured, for example, for the expansion to occur distal to thedistal end 708 of the outer tube 705. For example, the retractor caninclude retractor elements 751, 752 (not shown), 753 (not shown), 754,along with a proximal coupler 798 operably connected to the retractorelements 751, 752 (not shown), 753 (not shown), 754, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 751, 752 (not shown), 753 (not shown), 754. The retractor canbe configured to reversibly stiffen an otherwise flexible arrangement ofthe retractor, the arrangement designed to facilitate ease ofpositioning of the system 700 in a subject and to reversibly stiffen forthe expansion of the retractor in the subject. The stabilization of theretractor can, in some embodiments, include a means for stabilizing theretractor through a stabilizer subsystem as taught herein, thestabilizer having, for example, a flexible beam 770 that can beconverted to an at least substantially-rigid beam 775, using a means forslidably engaging a rigid, or substantially rigid, component 772 astaught herein in operable connection with the flexible beam 770, tosupport the expanded retractor.

FIG. 8 illustrates the cutaway view of FIG. 7, showing the distal end ofthe outer tube of a system as taught herein, in which components of thesystem can be floating in the outer tube to enhance flexibility forpositioning the system in a subject, according to some embodiments. Thefigure illustrates the distal end 808 of outer tube 805. The distal end808 includes a slot guide 855 to control the orientation of an expandingretractor element 851, as well as a lower retractor element 854.Likewise, a lumen 806 c can be provided to contain a working channel 810c. The lumen 806 of the outer tube 805 can also be used to guide anendoscope 815. Only a portion 851, 854, 870, 872, 875 of the retractorcomponents is shown to partially describe an embodiment of the relationbetween the outer tube 805 and the retractor. The retractor can beconfigured, for example, for the expansion to occur distal to the distalend 808 of the outer tube 805. For example, the retractor can includeretractor elements 851, 852 (not shown), 853 (not shown), 854, alongwith a proximal coupler 898 operably connected to the retractor elements851, 852 (not shown), 853 (not shown), 854, whether at leastsubstantially attached and/or at least slidably-engaged to the retractorelements 851, 852 (not shown), 853 (not shown), 854. The retractor canbe configured to reversibly stiffen an otherwise flexible arrangement ofthe retractor, the arrangement designed to facilitate ease ofpositioning of the system 800 in a subject and to reversibly stiffen forthe expansion of the retractor in the subject. The stabilization of theretractor can, in some embodiments, include a means for stabilizing theretractor through a stabilizer subsystem as taught herein, thestabilizer having, for example, a flexible beam 870 that can beconverted to an at least substantially-rigid beam 875, using a means forslidably engaging a rigid, or substantially rigid, component 872 astaught herein in operable connection with the flexible beam 870, tosupport the expanded retractor.

During a use of the system 800, the working channel 810 c can be afloating channel that is (i) at least substantially attached to thelumen of the outer tube at a first proximal location (not shown) and afirst distal location 806 c and (ii) at least substantially floating inthe lumen 806 of the outer tube 805 between the first proximal location(not shown) and the first distal location 806 c. Likewise, during theuse of the system 800, the endoscope 815 can be a floating endoscope 815that is (iii) at least slidably-attached to the lumen 806 of the outertube 805 at a second proximal location (not shown) and a second distallocation 806 a and (iv) at least substantially floating in the lumen 806of the outer tube 805 between the second proximal location (not shown)and second distal location (806 a). And, during the use of the system800, the working channel 810 c and the endoscope 815 also form separatefloating components of a floating arrangement that (v) at leastsubstantially increases the flexibility of the system 800 over a secondsuch system having separate lumens for a tool and an endoscope, theseparate lumens affixed to the lumen throughout the length of the outertube between the proximal end and the distal end of the outer tube, theincreased flexibility facilitating an ease of positioning the system 800in the subject for the treatment of the target tissue. In someembodiments, the endoscope 815 can be at least slidably-attached to thedistal end 808 of the outer tube 805 by inserting the endoscope 815through a dedicated port (not shown) for the endoscope 815, such thatthe system 800 is configured to be substantially limited to a slidingmovement in and out of the distal end 808 of the outer tube 805. And, insome embodiments, the endoscope 815 can be allowed to also float in aport 806 a that is substantially larger than the endoscope 815,providing a sliding motion for the endoscope as well as room forside-to-side movements as well.

FIGS. 9A and 9B illustrate side views of working, and/or floating,channels that can be used to guide tools as taught herein, according tosome embodiments. As discussed herein, the working channels can have atleast a portion of which floats in the lumen of the outer tube in amanner that is the same or similar to FIG. 8 to further enhance theflexibility of the outer tube during position of the system in asubject. In some embodiments, the terms “channel,” “floating channel,”“working channel,” and “tool channel” can be used interchangeably. Eachworking channel can be operatively connected to a handle 980 in a mannerthat is the same or similar to the operable connections taught hereinfor the retractor actuator and/or the stabilizer actuator. FIG. 9A showsthe tip 910 a of the working channel 910 in a substantially extendedposition, whereas FIG. 9B shows the tip 910 a of the working channel 910in a substantially bent position, such that the tip 910 a is deflectedsubstantially normal to the central axis of the working channel 910. Aworking channel system 900 consistent with other systems taught herein,for example, can include an entry port 908, a working channel 910, awire coupler 911, ratchet teeth 916, a pull wire 917 for flexing orextending the tip 910 a of the working channel 910, and wire actuator919. The ability to flex the tip 910 a of the working channel 910facilitates independent positioning of a tool (not shown) in thetreatment of a target tissue in a subject. In some embodiments, the wireactuator 919 can be multi-positional, having at least three positionsfor bending tip 910 a of working channel 910. In some embodiments, thewire actuator 919 can have a plurality of ratchet teeth 916 to provide aplurality of positions for reversibly-fixing the bent tip 910 a inposition during use of the tool (not shown) in the treatment of thetarget tissue in the subject.

As described herein, the channels can be configured to control thetrajectory and position of instruments such as forceps in the workingspace created by the retractor. In some embodiments, a channel can beremoved from, or inserted through, the outer tube of the system, aloneor inside an additional channel that may be used as a guide. Thechannels can be virtually any size considered by one of skill to beuseful in the systems described herein. For example, a channel can havean inner diameter ranging from about 1 mm to about 5 mm, from about 2 mmto about 4 mm, from about 1 mm to about 3 mm, or any range therein. Thelength of the channel should, of course, complement the length of thesystem. For example, the channel can have a length ranging from about40″ to about 72″, from about 48″ to about 60″, from about 42″ to about70″, from about 44″ to about 68″, or any range therein in increments of1″.

The channels can also comprise any material or configuration known toone of skill to be suitable for the uses described herein. For example,the channels can comprise a single polymer layer, multiple polymerlayers, a wire reinforced layer, or a combination thereof. In someembodiments, a channel can comprise (i) an inner layer of a polymer suchas, for example TEFLON or polyethylene for slippery luminal surface onthe inner diameter of the channel; (ii) a metal such as, for example, astainless steel, nitinol, or cobalt chromium as a wire reinforcement inthe configuration of a braid, mesh, or helical coil layer covering theinner layer; and, (iii) an outer layer of a polymer such as, forexample, PEBAX, polyurethane, polyethylene, silicone, PVC, or nylon.

In some embodiments, the channels can be configured such that the outerlayer (iv) is the most rigid in the proximal section of the channel(i.e., the first about 12″ to about 24″ of the channel), having ahardness of about 60 Shore D to about 80 Shore D; (v) has a mediumstiffness in the middle section (i.e., the next about 12″ to about 36″of the channel), having a hardness of about 50 Shore D to about 72 ShoreD; and, (vi) is the most flexible in the distal section (i.e., the nextabout 0.5″ to about 2″ of the channel), having a hardness of about 20Shore D to about 50 Shore D). The distal section of the channel can bethe section that flexes and can be the distal about 1″ of the channel,in some embodiments. In some embodiments, the channels can have a rigidsection just proximal to the distal section to keep this flexiblesection straight when there is a bending moment on the tip such as whenthe instrument which is inserted through the channel is grasping atissue during a gastrointestinal treatment, for example. The length ofthe rigid section of the channels can range, for example, from about 1cm to about 10 cm, from about 2 cm to about 8 cm, from about 3 cm toabout 7 cm, from about 4 cm to about 6 cm, about 6 cm, or any rangetherein in 1 cm increments. The rigid section can include a rigid tubecomprising a reinforcement material such as, for example, stainlesssteel or NITINOL, or a polymer such as PEEK or a polyimide embeddedbetween the outer polymer layer and the inner polymer layer. The rigidsection can have any suitable length to perform it's function in thesystem. In some embodiments, the rigid section can have a length rangingfrom about 0.001″ to about 0.005″.

The thickness of the inner layer of the channels can range from about0.0005″ to about 0.005″, from about 0.001″ to about 0.004″, from about0.002″ to about 0.003″, about 0.001″, or any range therein in 0.0005″increments. The thickness of the reinforcement layer can range fromabout 0.001″ to about 0.006,″ from about 0.002″ to about 0.005,″ fromabout 0.003″ to about 0.005,″ from about 0.001″ to about 0.003,″ about0.002″, or any range therein in increments of 0.0005″. The thickness ofthe outer layer can range from about 0.003″ to about 0.012″, from about0.004″ to about 0.010,″ from about 0.005″ to about 0.009,″ from about0.005″ to about 0.008,″ about 0.010″, or any range therein in incrementsof 0.001″.

For flexing the distal end of the channel, there can be a side lumenwith a pull wire embedded between the inner layer and the outer layer.In some embodiments, the side lumen can be located between the innerlayer and the reinforcement layer, or the side lumen can be a part ofthe inner layer. The side lumen can be made of any material consideredby one of skill to be useful in the systems taught herein. For example,the material can include a flexible tube of polymer such as, forexample, TEFLON or polyethylene. In some embodiments, the side lumenruns parallel to the length of the channel in the distal section of thechannel and then helical proximal to the distal section of the channel.The pitch of the helix can vary, for example, from about 1.0″ to about6.0″, from about 2.0″ to about 5.0″, from about 1.0″ to about 4.0″, fromabout 3.0″ to about 5.0″, about 4.0″, or any range therein in 0.1″increments. By routing the side lumen helically, the wire tension can bedistributed all around the shaft so that the shaft can be rotated in anyorientation smoothly and remain at least substantially stable. In someembodiments, the pull wire can run from the wire actuator in the handleinto the side lumen, out of the distal end of the side lumen, and loopedaround a rigid ring. The rigid ring (stainless steel, 0.002-0.005″thick, 0.040″-0.25″ long) at the distal end and back into the side lumenand out into the handle and attached to the wire actuator. The handlecan be operatively connected to the channel, the handle having ahousing, and a lumen in communication with the channel. The wireactuator is operatively attached to the pull-wire inside the housingwith a button on the outside of the handle allowing the wire actuator toslide back (proximal) and forth (distal) on the handle to pull and pushthe pull-wire. Pulling the wire makes the tip flex and become rigid,whereas pushing the wire can make the tip relax and straighten. Theslide has a means for locking the wire actuator in place, for example,using complementary ratchet teeth on the housing and wire actuatormechanism. When the wire actuator button is pressed, the ratchet teethcan disengage and unlock the pull-wire. In some embodiments, the tip canflex from about 0 degrees to about 150 degrees. In another embodiment,the tip can flexed from about 45 degrees to about 100 degrees. The canbe designed to be flexible in bending but stiff in torsion, allowing thechannel to follow the curvatures of the anatomy and allow for a rotationof the handle from outside the body during use, transmitting torque torotate the tip to a desired direction.

The working channels positioned inside the outer tube provide amulti-lumen catheter having manipulable passages for independentlymanipulating tools from outside the body into the working space insidecreated by expansion of the retractor. In some embodiments, from 1 to 3flexible tubes run inside of the outer tube and can be detached from theouter tube, as described herein, which facilitates the flexibility ofthe system. In some embodiments, these flexible tubes can be attached attwo points: (i) the proximal coupler of the retractor, which can be aring-type structure having ports at the distal end of the outer tube,and (ii) at the proximal end of the shaft, such as at the handle. Thiscan provide a floating arrangement in the outer tube that is unique,constraining the ends of the flexible tubes while allowing for asubstantially free-floating movement of the flexible tubes in the outertube to enhance the flexibility of the system.

In some embodiments, 2 inner tubes can be positioned adjacent to theinner surface of the outer tube to provide, effectively, 3 separatechannels. The 2 inner tubes can function as 2 independent workingchannels while the space between these first 2 working channels and theouter tube functions as a third channel. The third channel can besubstantially larger than the other 2 channels. Each of the first 2working channels can have, for example, an inner diameter ranging fromabout 2 mm to about 6 mm, about 3 mm to about 5 mm, or any rangetherein. In some embodiments, the diameter of the first 2 workingchannels can be about 4 mm. Each of the channels can be designed toaccommodate an endoscope such as a colonoscope, as well as tools thatinclude, for example, forceps, graspers, clip applier, dissectors,snares, electrical surgical probes, or loops. In some embodiments, thelargest diameter channel can be the channel for the endoscope.

The channel for accommodating the endoscope can be designed to have aninner diameter, for example, ranging from about 5 mm to about 15 mm,from about 6 mm to about 12 mm, from about 11 mm to about 14 mm, fromabout 5 mm to about 10 mm, from about 8 mm to about 13 mm, or any rangetherein in 1 mm increments. The inner tubes can comprise any suitablematerial known to one of skill to be useful for the purposes set-forthherein, as well as composites thereof. For example, the inner tubes cancomprises a fluoropolymer such as TEFLON for lubricity to ease tool orendoscope passage and movements. Other materials that may be usedinclude, for example, polyethylene, polypropylene, PEBAX, nylon,polyurethane, silicone, and composites thereof, each of which may alsobe used with a lubricant coating. The tubes may also comprise a metallicwire reinforcement such as a braid, mesh or helical coil, each of whichmay be embedded in the tube.

One of skill should appreciate that the systems taught herein can beused as a surgical suite with a floating, multi-lumen-catheter retractorsystem having a reversibly-stabilized and reversibly-expandableretractor for a minimally invasive treatment of a subject. In theseembodiments, the system can comprise a flexible outer tube for guiding afloating channel and a floating endoscope in a substantially floatingarrangement within the system. Due to the construction of the floatingsystem, the system is highly flexible, such that the flexible outer tubecan be highly flexible and have a lumen, a proximal end, and a distalend; and, the floating channel can serve as a guide through which a toolis manipulated in a treatment of a target tissue in a subject. Theretractor can be a reversibly-stabilized and reversibly-expandableretractor forming a treatment space upon expansion. The retractor can beconfigured, for example, for the expansion to occur distal to the distalend of the outer tube and to reversibly stiffen an otherwise flexiblearrangement of the retractor, the flexible arrangement designed tofacilitate the positioning of the system in the subject and toreversibly stiffen for the expansion of the retractor.

During a use of the system, the floating channel can be (i) at leastslidably-attached to the lumen of the outer tube at a first proximallocation and a first distal location and (ii) at least substantiallyfloating in the lumen of the outer tube between the first proximallocation and the first distal location. Likewise, during the use of thesystem, the floating endoscope can be (iii) at least slidably-attachedto the lumen of the outer tube at a second proximal location and asecond distal location; and, (iv) at least substantially floating in thelumen of the outer tube between the second proximal location and seconddistal location. And, during the use of the system, the floatingarrangement can (v) at least substantially increase the flexibility ofthe system over a second such system having lumens for a tool and anendoscope, the lumens affixed to the lumen of the outer tube throughoutthe length between the proximal end and the distal end of the outertube. The increased flexibility can facilitate an ease of positioning ofthe system in the subject; and, the reversibly-stiffened arrangement ofthe retractor can form an at least substantially rigid beam as astructural support for the expansion in the subject for the treatment ofthe target tissue.

In some embodiments, the retractor comprises at least two expandableretractor elements, each of the members having a proximal end and adistal end, the proximal end slidably engaged with the outer tube, andeach of the members configured such that an increase in the amount ofsliding of the proximal end toward the distal end compresses the memberand expands the retractor. These embodiments can also include a distalnexus located distal to the distal end of the outer tube and at whichthe distal end of each of the at least two retractor elements isaffixed; and, a stabilizer subsystem connecting the distal nexus to thedistal end of the outer tube and having an at least substantially rigidcomponent configured to reversibly stiffen an otherwise flexible portionof the retractor for an asymmetric expansion of the retractor.

In some embodiments, the retractor comprises four expandable retractorelements, each of the members having a proximal end and a distal end,the proximal end slidably engaged with the outer tube, and each of themembers configured such that an increase in the amount of sliding of theproximal end toward the distal end compresses the member and expands theretractor. These embodiments can also include a proximal couplerattached to the distal end of the outer tube, the proximal couplerhaving four retractor ports for the slidable engagement with the fourretractor elements, the four retractor ports positionedcircumferentially around the proximal coupler and configured tofacilitate a reversible, axial sliding of the retractor elements for theasymmetric expansion of the retractor. These embodiments can alsoinclude a distal nexus located distal to the distal end of the outertube and at which the distal ends of each of the four retractor elementsare affixed; and, a stabilizer subsystem connecting the distal nexus tothe distal end of the outer tube and having (i) a flexible componentthat extends from the proximal coupler to the distal nexus and (ii) anat least substantially rigid component that is slidably engaged with theproximal coupler and reversibly extends from the proximal coupler to thedistal nexus to reversibly-stiffen the retractor in an asymmetricexpansion of the retractor.

The flexible component and the rigid component can have central axesthat are each at least substantially parallel to the central axis of thedistal end of the shaft, the rigid component forming an at leastsubstantially rigid beam as a structural support for the asymmetricexpansion, the rigid beam having a luminal side and an abluminal side.

The systems provided herein can be used in several different methods oftreatment. For example, the systems can be used in a method of treatinga gastrointestinal lesion using a multidirectional and multi-angularapproach to the lesion. The method can include positioning the system ina subject's gastrointestinal tract, the positioning including placingthe retractor in proximity to a target lesion for a treatment; expandingthe retractor to create the treatment space for use of the tool;treating the lesion with the tool; collapsing the retractor; and,withdrawing the system from the subject. The lesion can include, forexample, a perforation, a tissue pathology a polyp, a tumor, a canceroustissue, a bleed, a diverticuli, an ulcer, an abnormal vessel, or anappendix.

It should be appreciated that there are a number of procedures andvariations, in addition to those taught above, that can be used readilyby one of skill in the implementation of the systems taught herein. Insome embodiments, one of skill can insert the endoscope through theendoscope channel of the system and extend the distal end of theendoscope distal to the distal end of the retractor to form an assembly.The assembly can then be inserted into a body lumen or orifice, such asthe colon, and advanced orally until the distal end of the scope or thelens is in proximity to the target tissue (lesion or defect) to betreated. The system is advanced forward over the scope until theretractor is positioned over the distal end of the endoscope whileobserving the image from the endoscope. The system is advanced until thetarget tissue is located between the proximal coupler and distal nexusof the retractor while observing the image from the endoscope. Thehandle or outer tube can be rotated to rotate the retractor so that thetarget tissue is at the desired position relative to the retractormembers while observing the image from the endoscope. The retractor canthen be straightened and stabilized by converting the flexible beam to arigid beam. The retractor can then be expanded by moving the retractionactuator forward on the handle while observing the image from theendoscope. This action pushes the tissue outwards, creates a workingspace around the target tissue, and anchors and stabilizes the targettissue. Optionally, while the retractor is expanded, the system can bepulled back to shift the peak of the most expanded members distally toimprove working distance between the endoscope and the peak of theasymmetric work space, wherein the peak is generally recommended to belocated around the target tissue. With the instruments inserted into theworking channels, insert the working channels into the proximal ports ofthe system and advance the instruments and channels distally until thetips of the working channels are distal to proximal coupler of theretractor while observing the image from the endoscope. At this time,the tips of the working channels can be flexed to the appropriateangulation for the tools to approach the lesion to be treated. Theworking channels can be rotated and moved axially as needed to thedesired position for the tools. Likewise, the instruments/tools can beadvanced relative to the distal end of the working channels as needed toextend the instruments as needed to reach the target tissue. Variousinstruments can be inserted through the working channels as desired, andboth the endoscope and the instruments can be advanced and positionedindependently into the working area to further manipulate and visualizethe target tissue at closer proximities or angulations. This is because,in some embodiments, the endoscope can also flex within the workingspace.

In some embodiments, it's desirable to have a means for delivering asystem taught herein with an optional cover, or sheath that covers aportion of the system, including the retractor during delivery of theretractor to a target site, during a treatment of a target tissue at thetarget site, during a removal of the target tissue, during a removal ofthe system from the subject, or a combination thereof. Recall that someembodiments of such an optional cover 355 have been illustrated herein,for example, in FIGS. 3A and 3K. One of skill will appreciate that theretractor has elements that can catch, snag, or otherwise disturb orcontact tissue during delivery, or removal, of the retractor to or fromthe target site. Also, the treatment of the target tissue may include,for example a dissection of tissue that can be performed within thecover without or intermingling the target tissue with the surroundingtissues. Moreover, the dissected tissue may be a cancerous tissue thatis desirable to contain during treatment or removal. The terms “cover”and “sheath” can be used interchangeably in many embodiments, and one ofskill can appreciate that such embodiments are open to improvements, astaught herein.

FIGS. 10A-10E illustrate a retractor sheath covering a retractor of asystem as taught herein, according to some embodiments. FIGS. 10A-10Cshow top-, oblique-, and side-views a flexible, clear sheath 1000 thatcovers a collapsed configuration of the retractor 1050 to render an atleast substantially smooth and/or atraumatic surface 1005 for a deliveryof the retractor 1050 to a target site (not shown) for a treatment of atarget tissue (not shown). In FIGS. 10A-10C, the cover is in a closedconfiguration that can be sustained until the expansion of the retractor1050 for the treatment, or it can be reversibly-obtained following thetreatment. FIGS. 10D and 10E show a top-view and side-view of anexpanded configuration of the retractor with the cover in an openconfiguration for the treatment.

The sheath 1000 can be designed to prevent or inhibit the retractorelements 1051, 1052, 1053, 1054 and bridges 1044 a, 1044 b fromcatching, snagging, or otherwise disturbing or contacting tissue duringa delivery or removal of the retractor 1050 to or from the target site.Note also, optional bridge retainer 1044 c used in operable connectionwith upper bridge 1044 a, for example. Such retainers can be used at anyposition around the retractor to facilitate a retention of theconfiguration of the working space 1060, for example, to retain theconfiguration under forces of the expansion of the retractor 1050.During the procedure the sheath 1050 can also prevent or inhibit tissuefrom entering the retractor 1050 until desired. The sheath 1050 can alsoact as a collection means for entrapping and/or pulling out a resectedtissue, which can be particularly desirable in the resection ofcancerous tissue in some embodiments. The sheath 1000 can be at leastsubstantially closed around the retractor 1050 during delivery, and canbe designed to open as the retractor 1050 is expanded to create theworking space 1060 for the treatment. As described herein, flexible beam1070 can be converted to the at least substantially rigid beam 1075using a means for the conversion as taught herein, for the expansion.

In some embodiments, the sheath 1000 can be perforated longitudinally(not shown), designed such that the sheath 1000 opens upon expansion ofthe retractor 1050 through tearing of the perforation at the targetsite. In some embodiments, a tongue-and-groove mechanism, for example aZIPLOCK mechanism, can be used to at least substantially close a slit1007 at the top of the retractor 1050 which can also open upon theexpansion of the retractor 1050 at the target site. In some embodiments,a larger perforation, or unclosed portion 1001, can remain in the sheath1000 to facilitate the tearing or opening of the sheath at the targetsite upon the expansion of the retractor 1050. In some embodiments, theterms “slit” and “opening” can be used interchangeably.

In some embodiments, the sheath can be reversibly opened, such that thesheath can be re-closable. For example, a drawstring, cable, or wire,can be operably positioned in communication with the opening for there-closing of the opening by pulling or pushing the drawstring, cable,or wire from outside the patient during the treatment. In someembodiments, the edges of the opening can form longitudinal pockets orchannels for pulling or pushing the drawstring, cable, or wire asdesired from outside the patient during the treatment, such as byrouting the drawstring, cable, or wire through the system and, perhaps,through the handle as with the other actuation means. In someembodiments, a drawstring is used to re-close the sheath, wherein thestrings can be tensioned at the handle to close the slit, or loosened toallow the retractor to expand. In some embodiments, the sheath has astiffening strip running transversely around the midportion of the cageto facilitate the cage wires expanding without catching on thesurrounding sheath. The stiffening strip can be another layer of thesheath welded or glued onto the existing sheath. It can also be formedas a thickened area. Alternatively, a stiffer material can be insertedin the pocket running transversely. The stiffening material may be thesame as that of the sheath or it may be a stiffer material.

One of skill will appreciate that any of the known materials and/ormethods of covering the sheath may be useful for the purposes taughtherein. For example, the sheath can range from about 10 mm to about 30mm at the ends that are attached to the proximal coupler and distalnexus, each of which can be used to define the ends of the retractor1050. Moreover, the sheath can be heat welded, glued, or heat-shrunk tothe proximal coupler and/or distal nexus, or perhaps substantiallyproximal or distal to these components, to fasten the sheath to theretractor. In some embodiments, the sheath may even cover the system asa sterilizing, or clean, cover, such that the sheath is an extension ofa disposable and/or replaceable component that may be applied, forexample, in a sterilization process. And, in some embodiments, thesheath can be larger at the mid portion where the diameter can range,for example, from about 20 mm to about 40 mm in a closed configuration.The sheath can be, for example, opaque, translucent, or clear, and thematerial composing the sheath can be, for example, a polyethylene,nylon, fluorinated ethylene propylene (FEP), TEFLON, polyethyleneterephthalate (PET), or polycarbonate. And, in some embodiments, thesheath material can range, for example, from about 0.0010″ to about0.0060″ thick, from about 0.0020 to about 0.0080″ thick, from about0.0030″ to about 0.0050″ thick, from about 0.0010″ to about 0.0030″thick, from about 0.0005″ to about 0.0100″ thick, about 0.0020″ thick,or any range therein in about 0.0005″ increments.

Without intending to be limited to any theory or mechanism of action,the above teachings were provided to illustrate a sampling of allpossible embodiments rather than a listing of the only possibleembodiments. As such, it should be appreciated that there are severalvariations contemplated within the skill in the art that will also fallinto the scope of the claims.

We claim:
 1. An endoluminal device for insertion into a body lumen of apatient, the endoluminal device comprising: a tubular member having atleast one lumen extending therethrough to receive an endoscopicinstrument and a distal opening communicating with the lumen andpositioned at a distal end of the lumen; and a chamber at a distalportion of the device, the chamber extending distal of the distalopening and lumen and including first, second and third connectedflexible retractor elements extending distal of the distal opening andlumen and a covering over a portion of the flexible retractor elementsto form with the flexible retractor elements an at least partiallyenclosed chamber distal of the distal opening and lumen with a sideaccess opening in the chamber to access target tissue, the chamberformed within a space between the flexible retractor elements and withinthe covering, the second and third flexible retractor elements connectedat a distal portion of the retractor elements and movable from a firstnon-expanded position for insertion into the body lumen of the patientto a second radially expanded position to create an increased workingspace and increased viewing space within the body lumen for performanceof a procedure on the target tissue, the first flexible retractorelement providing a stiffened structure along the chamber to stabilizethe chamber.
 2. The endoluminal device of claim 1, wherein the firstflexible retractor element transitions from a first flexible conditionto a second more stiffened condition by slidable movement of astiffening member further in a distal direction distally of the distalopening, the stiffening member axially slidable in a proximal directionto return the first flexible retractor element to the first flexiblecondition.
 3. The endoluminal device of claim 2, further comprising afirst actuator operatively connected to the stiffening member to movethe stiffening member in the distal direction from a retracted positionto an extended position.
 4. The endoluminal device of claim 3, furthercomprising a second actuator operatively connected to the second andthird flexible retractor elements to move the second and third flexibleretractor elements between the non-expanded and expanded positions,wherein the second actuator has multiple fixed positions for achievingmultiple fixed expanded positions of the second and third flexibleretractor elements.
 5. The endoluminal device of claim 1, wherein thefirst flexible retractor element forms a substantially rigid beam toprovide structural support for the chamber.
 6. The endoluminal device ofclaim 1, further comprising a transversely extending bridge memberattached to and spanning to extend between the second and third flexibleretractor elements for maintaining a desired orientation of the secondand third flexible retractor elements during expansion, the bridgemember stabilizing the second and third flexible retractor elements. 7.The endoluminal device of claim 1, wherein the tubular member isflexible and includes a second lumen dimensioned to receive an imagingdevice and a distal opening communicating with the second lumen, boththe distal opening communicating with the lumen to receive theendoscopic instrument and the distal opening communicating with thesecond lumen to receive the imaging device communicate with the chamber.8. The endoluminal device of claim 1, wherein the chamber in theexpanded position is asymmetrical to form an asymmetric working spacesuch that the first flexible retractor element is closer to a wall ofthe body lumen opposing the target tissue than it is to a wall havingthe target tissue.
 9. The endoluminal device of claim 1, wherein thesecond and third flexible retractor elements converge at a proximalportion and at a distal portion.
 10. The endoluminal device of claim 1,wherein the tubular member comprises a multi-lumen tube with at leasttwo working channels to receive an endoscopic instrument through eachworking channel.
 11. The endoluminal device of claim 1, wherein thetubular member comprises a multi-lumen tube to receive at least two toolchannels to guide insertion of endoscopic tools, the tool channels beingbendable to angle a distal end of the endoscopic tool insertedtherethrough.
 12. An endoluminal device for insertion into agastrointestinal tract of a patient for performing a surgical procedureon target tissue in the gastrointestinal tract, the endoluminal devicecomprising: a tubular member having at least one lumen formed therein toreceive an endoscopic instrument and a distal opening communicating withthe lumen, the distal opening positioned at a distal end of the lumen;and a chamber positioned distal of the distal opening and lumen andhaving a covering to form an at least partially enclosed chamber, thecovering having a side access opening communicating with the chamber,the distal opening providing an opening into the chamber, the chamberhaving a collapsed insertion position and at least one expanded positionto form a scaffolding to create an increased working space in thegastrointestinal tract, and further having a flexible condition and amore stiffened condition to stabilize the working space to resist movingforces within the gastrointestinal tract, and an elongatedlongitudinally extending substantially rigid beam extending distally ofthe distal opening and lumen forming part of the chamber causing thechamber to be in the more stiffened condition.
 13. The endoluminaldevice of claim 12, wherein the working space is an asymmetric workingspace, and the chamber includes a plurality of retractor elementsmovable to form an asymmetric chamber to increase a distance between acenter longitudinal axis of the endoluminal device and the targettissue.
 14. The endoluminal device of claim 12, wherein the chamberincludes a plurality of flexible elements and the substantially rigidbeam is slidable in an axial direction with respect to one of theflexible elements to stiffen the flexible element to create the morestiffened condition of the chamber, the substantially rigid beamreturnable through an opening in the tubular member to a first positionto return the flexible element to the flexible condition, and anactuator is operatively connected to the substantially rigid beam toslide the beam in the axial direction.
 15. The endoluminal device ofclaim 14, wherein expansion of the flexible elements isdisproportionately greater on a side between the stiffened flexibleelement and target tissue than on a side between the stiffening memberand an opposing wall of the tract.
 16. The endoluminal device of claim14, wherein the second and third flexible retractor elements converge ata proximal portion and at a distal portion, wherein the distal portionis distal of the distal opening and lumen.
 17. The endoluminal device ofclaim 12, further comprising a first actuator for reversibly moving thechamber between the collapsed and expanded position and a secondactuator operatively connected to the substantially rigid beam forreversibly transitioning the chamber between the flexible condition andmore stiffened condition.
 18. The endoluminal device of claim 12,wherein the substantially rigid beam is elongated such that a lengthwisedimension exceeds a transverse dimension.